This invention relates generally to fire doors, and more particularly to a panic bar controlled door which is made non-openable in response to occurrence of high temperature that heats the door, as during a fire.
Panic bars normally are operable, when pushed, to quickly unlock doors. During building fire conditions, it is sometimes desirable to render the door non-openable, so as to prevent spread of the fire through door openings.
There is need for apparatus as disclosed herein, and which serves this purpose in a very simple, reliable, and highly efficient manner.